Whatever happened was probably entirely legal and probably ethical as well. You can be a cofounder, and have ownership even if there is a lack of contracts and

Whatever happened was probably entirely legal and probably ethical as well. You can be a cofounder, and have ownership even if there is a lack of contracts and paperwork, and that likely would have come up during that $500M acquisition. I can't find it, but there was a Ycombinator - backed startup whose sale was blocked by a founder who went AWOL early. If he was an employee, or did otherwise hand over / accept compensation for his work, well, that's just business as usual: employees generating wealth for owners. The lesson is to have clarity of what you want out of a certain work, and then have some kind of contract, before you start working.